Various styles of socks are now available. One function of a sock is to mitigate the friction between the foot and the shoe. In achieving this function, it is desirable to maintain the relationship between the foot and the sock, to mitigate any abrasion caused by rubbing between the shoe, sock, and foot. The heel portion of a sock is often subjected to the most movement, as the user's heel moves with respect to the heel area of the shoe. Properly locating and retaining the user's foot with respect to the sock is a desirable feature. Similar concerns exist for other garments.
Commercially manufactured socks are produced using circular knitting machines. These machines employ needles mounted on a cylinder, or sometimes a double cylinder. The cylinder spins and the needles interlock loops of yarn. When the knitting process is complete, the sock appears as a tube that is open on both ends. The toe end of the sock is typically finished in a sewing or stitching operation. The sock described below is manufactured on these circular knitting machines.